The prevalence and factors associated with obesity and hypertension in university academic staff: a cross-sectional study in Bangladesh

Obesity is a major risk factor for hypertension, type 2 diabetes and other morbidities. On the other hand, hypertension is a leading cause of cardiovascular disease. The presence of obesity in hypertensive persons increases cardiovascular risk and related mortality. Data on the prevalence of obesity and hypertension in academic staff in Bangladesh are scarce. This study aimed to determine the prevalence and factors associated with obesity and hypertension among university academic staff in Bangladesh. In total, 352 academic staff were enrolled in this study from two universities in Bangladesh. A pre-structured questionnaire was used to obtain data on anthropometric, demographic and lifestyle-related factors. Bivariate and multivariate logistic regression analyses were performed to assess the factors associated with obesity and hypertension. Overall, the prevalence of general and abdominal obesity and hypertension was 26.7%, 46.9% and 33.7%, respectively. Female staff had a significantly higher prevalence of both general and abdominal obesity (41% and 64.1%, respectively) than male staff (21.5% and 34.9%, respectively) (p < 0.001). In contrast, male staff had a higher prevalence of hypertension (36.9%) than female staff (25.6%)(p < 0.001). An increased prevalence of hypertension was found in the higher BMI and WC groups of the participants. The prevalence of general obesity, abdominal obesity and hypertension was higher in the 30–40 years, > 50 years and 41–50 years age groups, respectively. According to the regression analysis, female gender and inadequate physical activity were independently associated with general and abdominal obesity. On the other hand, increased age, BMI, WC, presence of diabetes and smoking showed a significant association with hypertension. In conclusion, the prevalence of obesity and hypertension was higher among university academic staff members in Bangladesh. Our findings suggest that comprehensive screening programs are needed to facilitate the diagnosis, control, and prevention of obesity and hypertension in high-risk population groups.


Data collection.
A pre-tested questionnaire was used to collect data on anthropometrics (weight, height, body mass index, waist and hip circumference), demographic (age and sex), and lifestyle-related factors (physical activity and some food habits). The examinations and measurements were performed by two trained personnel. Anthropometric measurements were done according to the procedure described elsewhere 18,[25][26][27][28][29][30][31] . The measurements were done with light clothing and without shoes. Body mass index (BMI) was calculated by dividing the weight in kilograms by the height in meter square (kg/m 2 ). Blood pressure (BP) was measured with a digital BP machine (Omron M10, Tokyo, Japan). We advised the participants to take at least 10 min rest, then three consecutive BP measurements were taken 5 min apart. The first BP measurement was discarded and the average of 2nd and 3rd measurements was taken for systolic and diastolic blood pressures (SBP and DBP, respectively). Diagnostic criteria. The values of BMI were classified into underweight (< 18.5 kg/m 2 ), normal (18.5-23.5 kg/m 2 ), overweight (23.5-27.5 kg/m 2 ) and obese (> 27.5 kg/m 2 ) following guidelines suggested for the Asian population by WHO 32,33 . Abdominal obesity was diagnosed as a WC ≥ 80 cm for women and ≥ 90 cm for men 32,33 . Hypertension was diagnosed as SBP ≥ 140 mm Hg and/or, DBP ≥ 90 mm Hg and/or, current treatment for hypertension with antihypertensive drugs [34][35][36][37] . Prehypertension was diagnosed as SBP 120-139 mmHg; and/ or DBP 80-89 mmHg [34][35][36] . Participants with diabetes were identified by checking prescriptions provided by physicians and/or self-reported use of anti-diabetic medications. Physical activity was defined using the Global Physical Activity Questionnaire (GPAQ) developed by the WHO 38 . Physical activity was categorized as low or sedentary, moderate, and adequate or vigorous. Smoking status was classified into nonsmoker and current smoker.
Statistical analysis. Data are summarized as mean ± SD or percentages for the continuous and categorical variables, respectively. A chi-square test was used to assess the prevalence differences in the groups. Independent sample t-test and one-way ANOVA were used to measure the differences in the demographic and anthropometric variables. Bivariate and multivariable logistic regression analyses were performed to determine risk factors for hypertension and obesity. In regression models, the covariates such as age, sex, BMI, WC, presence of diabetes, physical activity, some food habits and smoking status were adjusted. The logistic regression results were expressed as odds ratio (OR) and 95% CI. Statistical data analyses were performed with the IBM SPSS Statistics version 23. A two-sided p-value < 0.05 was considered statistically significant.

Results
Characteristics of the study subjects. The demographic information of the study subjects by sex is summarized in Table 1. This study comprised 352 participants, 241 males and 111 females, aged 26-80 years. The mean age of the participants was 40.5 ± 10.3 years. The mean BMI was 25.7 ± 3.1 kg/m 2 with significant deference between males (25.3 ± 2.6 kg/m 2 ) and females (26.9 ± 3.9 kg/m 2 ) subjects (p < 0.001). Males had a higher mean of WC (88.3 ± 6.7 cm) than the female (84.4 ± 9.4 cm) subjects (p < 0.01).
The overall mean SBP and DBP were 121 mm Hg and 82.1 ± 10.2 mm Hg, respectively, with a higher mean value in males than in females (p < 0.001). About 22% of the participants were diabetic. Our data showed that 45.2% of the participants were habituated to consuming fat-rich food. Only 8.6% of subjects were familiar with adequate physical activity and 10.7% were used to smoking. www.nature.com/scientificreports/ pants were classified into four age groups, the prevalence of general obesity was higher in the 31-40 years age group, abdominal obesity was higher in the > 50 years age group and hypertension was higher in the 41-50 years age group. The prevalence of hypertension was significantly higher (p < 0.001) in overweight (57.4%) and obesity groups (31.7%) compared to the normal BMI (10.9%) group (Fig. 2). Similarly, hypertension prevalence was higher (50.6%) in the increased WC group compared to the normal WC (36.4%) group ( Fig. 2) although the difference was not statistically significant.

Assessment of the risk factors by logistic regression analysis. Both bivariate and multivariate
regression analyses were performed to determine the risk factors for obesity and hypertension. According to the analysis, female gender, increased WC, inadequate physical activity and low intake of vegetables were associated with the risk of general obesity (Table 3). In contrast, female gender, increased BMI and inadequate physical activity were the independent risk factors for abdominal obesity (Table 4). On the other hand, increased age, high BMI and WC, smoking and the presence of diabetes were the independent risk factors for hypertension among the study subjects (Table 5).

Discussion
The present study determined the prevalence and factors associated with obesity and hypertension in academic staff in Bangladesh. To the best of our knowledge, this is the first data on the prevalence of obesity and hypertension among academic staff members in Bangladesh. In our study, the total prevalence of general and abdominal obesity and hypertension was 26.7%, 46.9% and 33.7%, respectively. In the present study, females had a higher prevalence of both general and abdominal obesity (41% and 64.1%, respectively) than males (21.5% and 34.9%, respectively). Similar findings were reported in a recent study that included both rural and urban adults from all divisional regions in Bangladesh 20 . In that study, the prevalence Figure 1. Prevalence of general and abdominal obesity and hypertension among participants by gender (A) and age groups (B). **P < 0.001 when the prevalence of hypertension is compared between the gender groups and *P < 0.01 when the prevalence is compared within the age groups. P-values are obtained from the chi-square test. www.nature.com/scientificreports/ of general and abdominal obesity was 25.5% and 56.1% in females and 12.2% and 29% in male participants, respectively 20 which are also slightly lower than the prevalence rate found in the present study. Another recent study in Bangladesh reported an increased prevalence of overweight/obesity in females (45.6%) than in males (32.7%) 39 . A higher prevalence of both types of obesity was also reported among female participants in other studies performed in India 40 and China 41 . An increased prevalence of obesity in females might be related to excess calorie intake and low physical activity. Furthermore, using oral contraceptive pills, menopause and increased parity may also contribute to the development of obesity in females 42 . In our study, most of the participants were used to living in urban or suburban areas. In Bangladesh, a significant portion of the urban inhabitants is involved in comfortable office-related work. In addition, urban people are used to consuming a healthier and fat contained diet but do less physical exercise which may also influence excess weight gain among them. An increased prevalence of abdominal and general obesity was found in urban participants than in rural participants in a previous study in Bangladesh 20,43 . A higher prevalence of obesity was also reported in urban people in Mayanmar 44 and India 45 . It is important to mention that, a sedentary working environment and psychological stress may also increase the risk of obesity. A recent study reported that about 89% of university staff had moderate/high stress and only 25% of staff slept at least 8 h nightly 46 . There is also evidence that chronic stress may increase the risk of obesity as well as diabetes, hypertension, and cardiovascular disease 47 . Thus, a sedentary working environment and work-related stress may also contribute to the increased prevalence of obesity among our participants.
In our study, the participants had about twofold higher rates of abdominal obesity compared to the general obesity which suggests that a portion of the participants maybe were not diagnosed as obese based on their BMI values. Therefore, particular BMI cut-off values for both genders might be not sufficient to measure general obesity. In this case, age, gender and ethnic-specific BMI cut-off values may be more accurate for the diagnosis of general obesity. According to regression analysis, female gender, and insufficient physical activity were important risk factors for both types of obesity. Female gender and inadequate physical activity were also identified as the risk factors for obesity in the South Asian population 20,48 .
Some previous studies reported hypertension prevalence in the Bangladeshi general population; although, a variation in prevalence rate has been observed between the studies. An early review indicated the hypertension prevalence as 13.5% in Bangladeshi adults 49 . Another study reported the prevalence of hypertension at 27.4% in Bangladeshi adults 22 . A recent study that included data from rural and urban adults of eight divisional regions in Bangladesh reported the prevalence of hypertension at 30.9% 20 . The overall prevalence of hypertension in the Table 3. Bivariate and multivariable logistic regression analysis to assess the factors associated with general obesity. COR: Crude odds ratio, AOR: Adjusted odds ratio, CI: Confidence Interval.  20 . Among our study subjects, the prevalence rate of hypertension was significantly higher in males (36.9%) than in females (25.6%). A study conducted in the neighbouring country Pakistan also reported a higher prevalence of hypertension among university male staff (33.6%) than in the female staff (27.6%) 50 . An increased prevalence of hypertension was also reported among male staff (58.1%) than in the female staff (41.9%) of a university in Saudi Arabia 51 . Another study conducted among university staff in Malaysia also reported an increased prevalence of hypertension in male staff (45.5%) than in female staff (22.9%) 52 . In our study, increased age, increased WC and BMI, the presence of diabetes and smoking were the significant risk factors for hypertension. Similar results were found in other studies conducted in Bangladesh and other Asian countries 20,43,53 . Among the identified risk factors, the unmodifiable factor is age 54 ; therefore, in comprehensive programs, more attention needs to pay to the modifiable factors such as decreasing BMI, avoiding fatty food and smoking, doing regular physical exercise and control of diabetes 17,20,55 . In our study, we observed a higher rate of hypertension in overweight and obese groups. There is evidence that obesity is an independent risk factor for hypertension and they are often found together 11 . A significant portion of our study subjects was obese which may enhance hypertension and cardiovascular risk and related mortality. A high prevalence of overweight and prehypertension was also found among our participants (51.6% and 39.7%, respectively). The overweight and prehypertension are also public health concerns worldwide as they contribute to the development of obesity and hypertension in later life. Therefore, controlling normal BMI and blood pressure, eating a healthy diet and regular physical exercise can be effective in reducing the risk of obesity and hypertension among our participants. Finally, academic staff are an important population group of the nation; therefore, it is recommended to control obesity and hypertension to prevent cardiovascular diseases and related health consequences.
The main strengths of our study were that both genders were included in the study and we analyzed most of the demographic, anthropometric and lifestyle-related data. However, there were some limitations to our study. First, we measured obesity and blood pressure obesity data on a single day, therefore, a causal relationship could not be determined. Longitudinal studies are needed to identify all types of risk factors for obesity and hypertension among the academic staff. However, many of the similar did not measure blood pressure and obesity data several times. Second, our sample size was relatively small, therefore, the present data do represent the entire Table 4. Bivariate and multivariable logistic regression analysis to assess the factors associated with abdominal obesity. COR: Crude odds ratio, AOR: Adjusted odds ratio, CI: Confidence Interval.

Conclusions
The prevalence of obesity and hypertension was higher among university academic staff members in Bangladesh.
Our results showed that about 1 in 4, 1 in 2 and 1 in 3 of the academic staff were generally obese, abdominal obese and hypertensive, respectively. The prevalence of obesity was higher in female staff; whereas, hypertension was higher in male staff. Our study identified several risk factors that were associated with obesity and hypertension. The female gender and inadequate physical activity were independent risk factors for general and abdominal obesity. In contrast, age, BMI, WC, smoking and the presence of diabetes were the independent risk factors for hypertension. Our findings suggest that there is a need for comprehensive programs targeted at high-risk population groups such as females for obesity and males for hypertension. The comprehensive programs should focus www.nature.com/scientificreports/ on a healthy lifestyle, routine measurement of blood pressure, early diagnosis and treatment of the disease and increasing awareness to control and prevent obesity and hypertension among the academic staff in Bangladesh.

Data availability
The datasets used and/or analysed during the current study are available from the corresponding author upon reasonable request. www.nature.com/scientificreports/ Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http:// creat iveco mmons. org/ licen ses/ by/4. 0/.